package edu.neu.swc.skynet.advice;

import edu.neu.swc.skynet.annotation.IgnoreResponseAdvice;
import edu.neu.swc.skynet.vo.CommonResponse;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

/**
 * <h1>实现统一响应</h1>
 * 实现对返回请求的统一拦截
 * 限定在 edu.neu.swc.skynet 包
 */
@RestControllerAdvice(value = "edu.neu.swc.skynet")
public class CommonResponseDataAdvice implements ResponseBodyAdvice<Object> {

    /**
     * <h2>判断是否需要对响应进行拦截和处理</h2>
     * 通过扫描注解实现是否处理返回数据
     */
    @Override
    @SuppressWarnings("all")
    public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> aClass) {
        if(methodParameter.getDeclaringClass()
                .isAnnotationPresent(IgnoreResponseAdvice.class)){
            return false;
        }

        if(methodParameter.getMethod().isAnnotationPresent(IgnoreResponseAdvice.class)){
            return false;
        }
        return true;
    }

    @Override
    @SuppressWarnings("all")
    public Object beforeBodyWrite(Object o, MethodParameter methodParameter,
                                  MediaType mediaType, Class<? extends HttpMessageConverter<?>> aClass,
                                  ServerHttpRequest serverHttpRequest,
                                  ServerHttpResponse serverHttpResponse) {
        // 定义最终的返回对象
        CommonResponse<Object> response = new CommonResponse<>(0,"");
        if(null == o) {
            return response;
        }else if(o instanceof CommonResponse){
            response = (CommonResponse<Object>) o;
        }else{
            response.setData(o);
        }
        return response;
    }
}
